In a number of surgical or medical procedures, medical devices, e.g., tubes or catheters or electrical signal conducting leads, are introduced into the body of a patient, typically on a temporary basis to access a body cavity, vessel, duct or lumen or a body organ or muscle for diagnostic or therapeutic purposes or to provide drainage of a body organ or cavity. A variety of fixation mechanisms and systems are provided to maintain the distal end of the introduced catheter, tube or lead at the desired site that is initially accessed while allowing the patient to be ambulatory or to have some freedom of movement. If a fixation method or system is not provided, patient movement or interference with clothing or the bed, etc., can apply retraction or advancement forces to the implanted or inserted catheter, tube or lead causing it to be either further advanced or retracted possibly endangering the patient or causing patient discomfort and failure to perform its intended function. The fixation mechanisms operate either passively or require activation during the implantation or insertion procedure. The fixation mechanism must be disabled or otherwise released to allow retraction of the catheter, tube or lead from the body when its purpose is served.
In the field of temporary cardiac pacing or monitoring, electrical leads are introduced percutaneously through the vascular system to locate distal pace/sense electrode(s) within a heart chamber or cardiac vessel or are extended from the exterior of the heart through the skin incision following cardiac surgery to conduct pacing pulses and the sensed electrogram between the heart and an external pacemaker pulse generator. Similarly, electrical leads are introduced percutaneously into selected muscle groups or into the spinal column to provide muscle and nerve stimulation and other sensor bearing leads can be inserted into the body to sense other physiologic conditions, e.g., temperature, blood gases, blood pressure or the like. The externally extending proximal portions of such leads are typically held in place by adhesive bandages or the like applied over the lead body or winged flaps of the lead body and against the patient's skin. In some instances, the lead distal tips are configured to provide some resistance to accidental withdrawal. Withdrawal is effected by traction applied to the lead body outside the skin. Similar methods and approaches have also been employed to secure drainage tubes or catheters extending subcutaneously into a body cavity, lumen, vessel or duct, etc.
Gastrostomy tubes or catheters are placed percutaneously through the patient's skin, the underlying abdominal wall and the gastric or stomach wall and into the stomach cavity in order to provide nutrients to a patient who is unable to chew or swallow food as described, for example, in U.S. Pat. Nos. 4,705,040, 5,007,900, 5,151,086, 5,273,529 and 5,458,583, all incorporated herein by reference. In this procedure, it is necessary to ensure that the distal end of the gastrostomy catheter remains within the stomach, and that the stomach wall is sealed against the catheter to inhibit leakage of stomach fluids into the peritoneal cavity or all the way through the puncture. The stomach wall and the abdominal wall are pulled together and then held in contact by insertion of a plurality of T-fasteners at spaced apart locations to form a contact area or field through which the gastrostomy catheter can be introduced via a stoma tract as disclosed in the above-incorporated '040, '086 and '583 patents. It may be necessary to leave the gastrostomy catheter in place for weeks or months, and the stomach wall and abdominal wall adhere together and a tissue layer forms around the stoma tract.
The gastrostomy catheter itself is held in place extending through the stoma tract typically by adhesion to the patient's skin and/or by use of various forms of stabilization and sealing mechanism. For example, in the above-incorporated '529 or '583 patents, the gastrostomy catheter includes an expandable Mallecot tip or an inflatable balloon, respectively, adapted to be received in the stomach cavity and expanded therein to bear against the stomach wall. External retention rings surrounding the catheter body proximal to the balloon bear against the patient's skin around the stoma tract. In the '583 patent, the balloon can be inflated within the stomach cavity, and the retention ring that can be pushed against the skin to draw and compress the annular balloon against the stomach wall surrounding the stoma tract and to seal it from leakage. In the '900 patent, the gastrostomy catheter distal end is formed with a resilient T-bar that normally extends transverse to the catheter axis but can be straightened out during insertion through the stoma tract and can then be released within the stomach to inhibit retraction. An external ring is also provided that can be applied against the skin to compress the stomach wall and abdominal wall together in the area surrounding the stoma tract and catheter body extending therethrough. In these approaches, the location of distal tip of the gastrostomy or jejunostomy catheter in the stomach or small intestine is fixed adjacent to the stoma tract by operation of the fixation mechanism and cannot be inserted to a desired site.
Similar procedures can be followed in performing a jejunostomy to access the small intestine using a jejunostomy tube or catheter that has a longer catheter body than a gastrostomy catheter as described in the above-incorporated '086 patent. A combined gastrostomy and jejunostomy or gastro-jejunal catheter is also known for accessing both the stomach cavity and the small intestine. Generally, short and long catheter lumens are incorporated into the catheter body, in either a side-by-side or co-axial arrangement of an inner and outer catheter body. The shorter catheter lumen terminates in end and/or side holes located in the stomach cavity, and the longer catheter lumen terminates in end and/or side holes located in the small intestine. Such a co-axial gastro-jejunal tube or catheter is disclosed in U.S. Pat. No. 4,685,901, incorporated herein by reference. In the '901 patent, a balloon on the outer catheter is inflated in the stomach and an exterior plate is brought to bear against the skin to draw the balloon against the stoma opening to close it and to hold the gastro-jejunal tube in place.
Drainage tubes or catheters are frequently introduced percutaneously through a surgically created tract into a body cavity or organ to simply provide drainage of fluids that accumulate therein following surgery, for example. Drainage catheters are usually simply taped to the skin at the incision without any stabilization provision or system. However, in some cases stabilization is provided using an inflatable balloon and external ring system as described above or an expandable Mallecot tip of the type described in the above-incorporated '529 patent or a Cope loop that is formed by a retraction of a distal section of the catheter within the cavity into a curve by retracting a filament extending outside the skin.
Other tubes or catheters are inserted into existing body tracts, vessels or lumens, etc. In urinary catheterization procedures, catheters are introduced through the uretha into the bladder to facilitate drainage after an injury or surgical procedure. Typically, the distal portion of the catheter has an inflatable balloon attached to it that is inflated in the bladder after the urinary catheter is inserted therein to resist unintentional retraction. Naso-gastric catheters are extended to the stomach cavity through a patient's nasal cavity and esophagus, and are often held in place by taping an exposed section about the patient's nose.
Some of these attachment mechanisms are bulky and difficult to use in a body vessel, duct or tract or surgically created incision or stoma tract or the like and frequently require them to be dilated to pass the catheter or tube and its internal retention mechanism through them. For example, inflatable balloon retention mechanisms can increase the diameter of a catheter by 2-4 French when the balloon is deflated.
In addition, these internal retention mechanisms (other than simply employing adhesive tape or the like around the body of the catheter, tube or lead and against the patient's skin) are formed as part of the catheter, tube or lead body. Their retention strength and capability to be employed in a given application are limited by the size and strength of the catheter body. If the catheter body is necessarily soft and pliant, it may provide a weak support for the internal attachment mechanism.
A number of such problems exist with current retention mechanisms used within the stomach cavity to retain the gastrostomy or jejunostomy or combined gastro-jejunal tubes or catheters in place. The inflatable balloons add to the size of the catheter body when deflated and cause the stoma cavity to be dilated as the deflated balloon is inserted through it. Then, leakage of stomach acid into the peritoneal cavity or onto the skin can occur through the dilated stoma around the catheter body. To avoid this problem, the balloon wall is made of thin, stretchable material. Such balloon walls are fragile and can break during installation and are degraded over time by stomach acids to the point where they break. The expandable Mallecot tip is bulky and can be difficult to retract through the stoma tract when it is desired to do so, but paradoxically can sometimes fail to retain the catheter in the stoma tract. The filament employed to bend the catheter distal end into the Cope loop often breaks where it is attached to the catheter tip because the catheter body has to be soft and pliable. Tension applied to the filament to maintain the Cope loop can sometimes quickly cause it to separate from the catheter tip, causing the tip to straighten and the catheter to fall out or be drawn out of the stoma tract. All of these retention mechanisms also suffer from low "pull strength", that is the force required to overcome the retention mechanism and to pull the catheter out of the stoma tract is relatively low. Often, these catheters are inadvertently pulled out of the stoma tract, causing stomach acids to escape and causing discomfort to the patient.
The gastrostomy or jejunostomy or combined gastro-jejunal tube or catheter is intended to be coupled at its proximal end to a nutrient container and periodically used to infuse liquid nutrients through its lumen and into the stomach or small intestine cavity. The catheter lumen can become clogged over weeks or months of usage, and it is inconvenient or not possible to clean it. Consequently, it may be necessary to replace the gastrostomy or jejunostomy catheter simply to provide a usable catheter lumen.